working principle

Linear motor is a kind of transmission device which converts electric energy directly into linear motion mechanical energy without any intermediate conversion mechanism. It can be seen as a rotating motor which is split radially and unfolded into a plane. The side from the stator evolution is called primary, and the side from the rotor is called secondary. In practical application, the primary and secondary are manufactured into different lengths to ensure that the coupling between primary and secondary is constant in the required travel range. Linear motor can be short primary long secondary, or long primary short secondary. Considering the manufacturing cost and operation cost, the short primary and long secondary are generally adopted.

The working principle of linear motor is similar to that of rotary motor. Take the linear induction motor as an example: when the primary winding is connected with the AC power supply, the traveling wave magnetic field will be generated in the air gap. Under the cutting of the traveling wave magnetic field, the secondary winding will induce the electromotive force and generate the current, which will act with the magnetic field in the air gap to generate the electromagnetic thrust. If the primary is fixed, the secondary moves in a straight line under the action of thrust; On the contrary, the primary do linear motion. A linear motor application system must not only have a good linear motor performance, but also have a control system which can achieve the technical and economic requirements under safe and reliable conditions.

Working characteristics

Because linear motor can produce linear motion without any intermediate conversion mechanism, it is especially suitable for linear motion. Compared with the traditional rotary motor, the device driven by linear motor has the following advantages

advantage

(1) The middle mover of the linear motor can be directly connected with the load to produce linear motion without intermediate transmission mechanism such as chain and lead screw, which can greatly improve the transmission efficiency.

(2) Because there are few connecting accessories in the middle drive, the structure of linear motor motion system is simple, and the noise interference caused by mechanical friction is reduced. Because of its simple structure, it can greatly improve the reliability of the system.

(3) Linear motor can produce higher linear speed through its own larger acceleration in a short stroke.

(4) Linear motor is not bound by centrifugal force, so its linear speed is unlimited.

(5) The primary shape of linear motor is regular and easy to package. The armature winding can be packaged with epoxy resin and other chemical materials to protect it from the invasion of chemical liquid or rain. It can be more easily used in harsh working environment.